This is getting worse and worse though as browsers expose more and more of their host operating system's functionality. The benefits of using a website instead of a native app are quickly disappearing, while the drawbacks have only been somewhat mitigated. We're getting to the point where browsers are worthy of the decades old criticism Emacs has received. They have eventually become an OS with many fine features - simply lacking a good web browser. For the privacy conscious user, modern web technologies will undermine you every step of the way, or simply break if you choose to stand your ground.
I personally would rather have a dozen well crafted battery sipping native C apps than a million awful contraptions built in a script interpreter on to of a VM by the lowest bidder on ODesk. Sure it's harder to do it right, but that's the cost of quality. Maybe I'm stuck in the 80's, but to me, it seems like a lot of wisdom has been shrugged off in the pursuit of expedience.